Parts for mechanical devices, such as airplanes or automobiles, are often machined from pieces of metal or other hard substances with machine tools such as drills. For instance in the aircraft industry, wing and fuselage parts are cut to design specifications from pieces of aluminum and then further drilled and reamed to allow attachment with related wing and fuselage parts.
Parts must often be machined to exact tolerances. However, the process of cutting and drilling metal can often introduce imperfections. For instance, machining metal creates heat which can warp the metal and can deteriorate the cutting point of the machine tools being used. To limit the effects of heat and the deterioration of cutting points, machinists commonly use lubricating devices to lubricate and cool the cutting point of the machine tool as it cuts or drills the metal. For instance, the Quackenbush air-powered drill sold by Intool Incorporated has a mist lubricator which directs a mist of lubricant/coolant at the work piece through a ported head attached near the cutting point of the drill bit. Air pressure forces a lubricating agent from a reservoir into a separate air stream which is directed to ports that meter out predetermined amounts of selected lubricating agents against the cutting point of the drill in the form of a mist. This lubricating mist decreases the heat produced by the cutting or drilling process and also helps to preserve the life of the cutting point. However, this mist lubricator is bulky and inconvenient because it uses separate air lines to supply air pressure to force lubricant from the reservoir that holds the lubricant supply and to pick up the lubricant for distribution to the cutting point of the drill.
Imperfections can also be introduced in the machining process by sudden or irregular movements of the machining tools. When precise tolerances are needed for machine jobs, machinists often use hydraulic feed controls to control the rate of application of the machine tool to the work piece. Hydraulic feed controls are typically attached to the machine tool and have a plunger that rests against the work piece being machined. When force is applied against the plunger, for instance by the application of a drill to a work piece, the plunger compresses hydraulic fluid in a cylinder to provide a counter-force which ensures that the machine tool will not move at an excessive rate. Thus, for instance, a machinist drilling through a material can avoid the sudden movements which often occur when a drill meets reduced resistance as it passes through the material. Such hydraulic feed controls are sold by Deschner Corporation under the trade name KINECHEKS.RTM., and are disclosed in U.S. Pat. No. 3,027,152, U.S. Pat. No. 3,244,013, and U.S. Pat. No. 4,257,499, each by Deschner. These devices are built to withstand large forces without leaking any hydraulic fluids.
In the aircraft industry it is common to have both a KINCHEK.RTM. device and a mist lubricator attached to a drill when holes are drilled through a material. However, these accessories add weight and can reduce the versatility of the drill. For instance, the drill, lubricant reservoir and mist distribution ports can each require a separate air line, and the lubricant and KINECHEK.RTM. devices each have separate reservoirs for storing hydraulic or lubricating fluid. In addition, having two devices increases the expense of the machining process. KINECHEK.RTM. devices in particular add expense because they are built with heavy-duty seals that will withstand large forces without leaking. Further, having two devices complicates the machining process since the machinist must understand both devices and incorporate each device in his operation. For instance, the machinist must generally initiate the flow of mist lubricants by a step separate from the initiation of the drilling process itself by supplying air to the lubricant reservoir and the distribution ports.